Swivel jack assembly

ABSTRACT

The assembly incorporates two plates. There are annular protrusions on one plate and a matching annular groove on the other. A central bolt and washer holds the plates in engagement while permitting rotation of one plate relative to the other. The cooperating annular grooves and protrusions transfer loads between plates. Ninety degrees of rotation causes the jack assembly to rotate from the vertical stowed position to the horizontal towed position.

FIELD OF THE INVENTION

The present invention relates generally to the field of swivel jacks fortowed vehicles such as trailers.

BACKGROUND OF THE INVENTION

Swivel jacks are used with trailers to vertically position the trailertongue so that it can be mounted onto a hitch of a towing vehicle. Theswivel jacks keep the trailer level when the trailer is disengaged fromthe towing vehicle. Typically these jacks are pivotably mounted onto thetrailer tongue such that they can be pivotally moved to a horizontallystored position when not in use. The jack tube swings from itshorizontal transit position to the vertical stationery position, lockingsecurely into place with a spring-loaded pin.

Current swivel jacks are comprised of two brackets connected togetherwith a bolt. The design of the brackets causes the center bolt to takethe entire load, which could result in the bolt being sheared off orworn down. What is needed is an improved swivel jack that disperses theload from the bolt to other areas of the jack assembly.

SUMMARY OF THE INVENTION

The present invention provides a swivel jack assembly for dispersingload from a bolt to other areas of the swivel jack assembly. The swiveljack assembly is comprised of a mounting bracket welded or bolted to anelongated tubular housing of a jack. Attached to the mounting bracket isa first rotatable plate having an annular circular groove. The annulargroove accepts the annular protrusions of a second rotatable plateallowing the first rotatable plate to rotate within the second rotatableplate. A bolt and washer secure the first rotatable plate to the secondrotatable plate and a releasable latch secures the jack in either anupright position or a towed position. The annular grooves disperse theload from the bolt to other areas of the jack assembly so that the boltwill not be sheared off or be worn down.

The foregoing, together with other features and advantages of thepresent invention, will become more apparent when referring to thefollowing specification, claims and accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

The present invention will be better understood from the followingdetailed description of an exemplary embodiment of the invention, takenin conjunction with the accompanying drawings in which like referencenumerals refer to like parts and in which:

FIG. 1 illustrates the swivel jack assembly of the present invention;

FIG. 2 illustrates a top view of the swivel jack assembly of the presentinvention;

FIG. 3 illustrates a front view of the second rotatable plate;

FIG. 4 is a side view of the second rotatable plate illustrated in FIG.3;

FIG. 5 is a cross-sectional view of the second rotatable plateillustrated in FIG. 3;

FIG. 6 illustrates a front view of a first rotatable plate;

FIG. 7 illustrates a cross-sectional view of the first rotatable plateillustrated in FIG. 6; and

FIG. 8 illustrates a front view of the jack assembly of the presentinvention.

DETAILED DESCRIPTION OF THE DRAWINGS

FIG. 1 illustrates the swivel jack assembly of the present inventionwhich is mounted onto the side of a trailer tongue (not shown). The jackincludes an elongated tubular housing 4, which telescopically receives atube for raising and lowering the trailer tongue, and a wheel 1 on thelower end of the tubular housing so the trailer can be easily moved whendetached from a towing vehicle. The tube is raised and lowered out ofthe elongated tubular housing by turning a handle 7 located on the jack.A mounting bracket secures the elongated tubular housing to a firstrotatable plate, which is attached to a second rotatable plate by a boltor screw. The mounting bracket is welded or bolted to the trailer tongueattaching the jack assembly to the trailer tongue. A releasable latch 3is provided on the jack in order to hold the jack in either a horizontaltowed position or a vertical stowed position. The jack is utilized tolower and raise the trailer tongue to facilitate engagement of thetrailer to and disengagement of the trailer from a towing vehicle. Whenthe trailer is disengaged from the jack, the jack supports the tonguefrom the ground and helps keep the trailer in a level position. When thejack in is the towed position, the jack is parallel to the trailertongue.

Turning to FIG. 2, a top view of the swivel jack assembly of the presentinvention is illustrated. The elongated tubular 4 housing is attached toa mounting bracket 5, which is attached to a first rotatable plate 6 anda second rotatable plate 8 with a nut 10 and bolt 12 and washer 13. Thewasher 13 disperses the bolt load over the larger surface of the firstrotable plate 6 so that the bolt 12 will not be sheared off or worndown. Annular protrusions on the surface of the second rotatable plateand a circular annular groove on the back surface of the first rotatableplate 6 allow the first rotatable plate 6 to easily rotate independentof the second rotatable plate 8 so the jack can be in an engaged uprightposition or a disengaged towed position for traveling. By pulling on thereleasable latch 3, the jack is allowed to move from the uprightposition to the towed position and vice versa.

FIG. 3 illustrates a front view of the second rotatable plate 8. Thesecond rotatable plate 8 includes four annular grooves (16, 20, 22, 23)protruding from the top surface of the plate and a hole for insertion ofthe bolt 12 to secure the plate 8 to the first rotatable plate 6. Thefour annular grooves (16, 20, 22, 23) are provided so the jack can beeasily rotated. Although in the preferred embodiment of the presentinvention, four annular protrusions are shown on the top surface of thesecond rotatable plate 8, the second rotatable plate 8 may be comprisedof a greater number or a lesser number of annular protrusions, howeverthere must be at least one annular protrusion. FIG. 4 is a side view ofthe second rotatable 8 plate illustrated in FIG. 3 and FIG. 5 is across-sectional view of the second rotatable 8 plate illustrated in FIG.3.

FIG. 6 illustrates a front view of the first rotatable plate 6. Thefirst rotatable plate includes a circular groove 16 for acceptingannular protrusions allowing the first rotatable 6 plate to rotate whichin turn allows the jack to rotate between the engaged and disengagedpositions. Also included on the first rotatable plate 6 is a pair offlanges for securing the first rotatable plate 6 to the mounting bracketand a hole 25 for insertion of the bolt to secure the plate to thesecond rotatable plate 8.

FIG. 7 is a cross-sectional view of the first rotatable plate 6illustrated in FIG. 6 attached to the mounting bracket 5, which isattached to the tubular housing 4 of the jack. Also shown in FIG. 7 is ahole 25 which receives bolt 12. The jack assembly of the presentinvention also comprises a locking mechanism to prevent unwantedmovement of the jack. The locking mechanism is comprised of thereleasable latch and the first and second rotatable plates shown inFIG. 1. Upon pulling on the releasable latch, the jack is released andcan be rotated into either an upright position or a towed position. Theannular protrusions of the second rotatable plate 8 are disposed in theannular groove of the first rotatable plate 6, which enables pivotalrotation of the first rotatable plate 6. When the first rotatable plate6 is in the correct position, that is either in the engaged uprightposition or a disengaged towed position for traveling, the releasablelatch is released causing a pin to be inserted into the jack assemblylocking the jack in position.

FIG. 8 illustrates a front view of the jack assembly of the presentinvention. The elongated tubular housing 4 is attached to the firstrotatable plate 6 comprising the annular groove so the second rotatableplate (not shown) can rotate. Also shown in FIG. 8 is the releasablelatch 3 to hold the jack in the proper position.

Although an exemplary embodiment of the invention has been describedabove by way of example only, it will be understood by those skilled inthe field that modifications may be made to the disclosed embodimentwithout departing from the scope of the invention, which is defined bythe appended claims.

1. A swivel jack assembly for dispersing a load, the swivel jackassembly comprising: a mounting bracket affixed to an elongated tubularhousing of a jack; a first plate secured to the mounting bracket, thefirst plate having a first inner portion and a first outer portion inthe same vertical plane, and having a first aperture in the center ofthe first inner portion and a groove forming a circular ring separatingthe first inner portion and the first outer portion; a second platesecured to a trailer tongue, the second plate having a second innerportion and a second outer portion in the same vertical plane, andhaving a second aperture in the center of the second inner portion and aplurality of protrusions forming a discontinuous circular ringseparating the second inner portion and the second outer portion; a boltpassing horizontally through the first aperture in the first plate andthe second aperture in the second plate, securing the first plate to thesecond plate, and adapted so that when the groove of the first plateaccepts the plurality of protrusions of the second plate and a load isapplied to the swivel jack, the groove bears a load at an upper arc ofcontact between the groove and the plurality of protrusions above thebolt, and the groove bearing a load at a lower arc of contact betweenthe groove and the plurality of protrusions below the bolt; and areleasable latch for securing the jack in either an upright position ora towed position, the releasable latch comprising a pin securing thefirst plate to the second plate, wherein the load is distributed betweenthe upper arc of contact and the lower arc of contact.
 2. The swiveljack assembly of claim 1, further comprising a tube, the tubular housingtelescopically receiving the tube for raising and lowering the trailertongue.
 3. The swivel jack assembly of claim 2, further comprising awheel on the lower end of the tubular housing for easily moving atrailer attached to the jack assembly.
 4. The swivel jack assembly ofclaim 1, wherein the jack is released and can be rotated into either anupright position or a towed position when releasing the releasablelatch.
 5. The swivel jack assembly of claim 1, wherein the first platerotates around the bolt with respect to the second plate so the jack canbe in an engaged upright position for supporting the trailer tongue or adisengaged towed position for traveling.
 6. (canceled)
 7. (canceled) 8.The swivel jack assembly of claim 1, further comprising a tube insidethe elongated tubular housing which is raised and lowered by turning ahandle located on the jack.